Slack agent-to-agent rooms (SLACK_A2A_ROOMS)

Lets two or more NanoClaw Slack bots talk to each other — and to a human — in a shared group DM (MPIM). Empirically established against live Slack: conversations.open with users=[<human>, <other bot user id>…] works from a bot token holding mpim:write and returns an is_mpim channel, and bots receive each other's messages over their own Socket Mode connections as plain message events with channel_type: "mpim", bot_id set, and subtype null.

Canonical home. This directory on main is the skill's canonical source — the setup wizard and any direct apply read it from the checkout. The copy on the channels branch is a compatibility mirror for older checkouts whose setup fetches companions from there; edits land here, never there.